<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>

  <body>
    <div id="app">
      <div>
        <p>请选择你要购买的书籍</p>
        <ul v-for="(item,index) in arr" :key="index">
          <li>{{ item.name }} <button @click="payName(index)">买书</button></li>
        </ul>
        <table border="1" width="500" cellspacing="0">
          <tr>
            <th>序号</th>
            <th>书名</th>
            <th>单价</th>
            <th>数量</th>
            <th>合计</th>
          </tr>
          <tbody>
            <tr v-for="(item,index) in arr" :key="index">
              <td>{{ index + 1 }}</td>
              <td>{{ item.name }}</td>
              <td>{{ item.price }}</td>
              <td>{{ item.count }}</td>
              <td>{{ item.price * item.count }}</td>
            </tr>
          </tbody>
        </table>
        <p>总价格为:{{ totalPrice }}</p>
      </div>
    </div>
    <script src="./vue.js"></script>
    <script>
      const app = new Vue({
        el: "#app",
        data: {
          arr: [
            {
              name: "水浒传",
              price: 107,
              count: 0,
            },
            {
              name: "西游记",
              price: 192,
              count: 0,
            },
            {
              name: "三国演义",
              price: 219,
              count: 0,
            },
            {
              name: "红楼梦",
              price: 178,
              count: 0,
            },
          ],
        },
        methods:{
            payName(id){
                // console.log(name)
                // this.arr.filter(item => item.name === name)
                this.arr[id].count++
            }
        },
        computed:{
            totalPrice(){
                return this.arr.reduce((sum,item)=> sum + item.count * item.price ,0)
            }
        }
      });
    </script>
  </body>
</html>
